Surfboard with nose and/or midsection lift generating means



m, W66 J. M. KELLY, JR 9 3 7 SURFBOARD WITH NOSE AND/OR MIDSECTION mm GENERATING MEANS Filed NOV. 10, 1965 2 Sheets-Sheet 1 r "32 I l M i \NVENTOR ATTORNEY 5 JOHN M. KELLY, JR.

w 9 M2 J. M. KELLY, JR 2,222,222

SURFBOARD WITH NOSE AND/OR MIDSECTION LIFT GENERATING MEANS Filed Nov. 10, 1965 2 Sheets-Sheet 2 INVENTOR Z2 4 i JOHN M. KELLWQJR,

ATTORNEY United States Patent 3,289,227 SURFBOARD WITH NOSE AND/0R MIDSECTHON LIFT GENERATING MEANS John M. Kelly, J12, 4117 Black Point Road, Honolulu, Hawaii Filed Nov. 10, 1965, Ser. No. 507,185 16 Claims. (Cl. 9-610) This invention relates to a surfboard.

At present, conventional surfboards consist of a buoyant member curved upward at the front and rear ends to enable a smooth sliding movement over the forefront of a wave. The front ends of conventional surfboards are convexly curved both transversely and longitudinally on the underside, the longitudinal curvature acting to prevent the forward tip from catching irregularities on the waters surface, and the transverse curvature acting to ease the boards impact on wind chop and prevent slapping.

A popular style of surf riding today consists of the rider walking to the longitudinal center or forward end or nose of the board when it is in a position on and has motion across the upper portion of the crest of the nearly breaking wave. The speed of the board provides a certain limited amount of lift on the underside of the nose of the board sufficient to support the riders weight. However, when the wave is too small or too slow or the riders trimmed position on the wave is insufficient to generate this lift, the nose of the board dives under water and spills the rider off. The transverse and longitudinal convex curvature of the bottom or underside of the front end of the aforesaid conventional surfboards causes the displaced water to slip out easily in a sidewise manner thereby limiting the lift effect to the width of the board and its speed across the water.

The primary object of this invention is to provide a surfboard with means at the underside of the nose and/ or middle portion thereof which acts to overcome the disadvantages mentioned hereinb'efore that reside in conventional surfboards when employed in the longitudinal center or nose riding position.

Another object of the invention is to provide a surfboard of the character above described in which the means at the underside of the middle and nose portion comprises concave or slotted areas or combinations thereof which trap the sidewise-displaced water, converting it into lift and thus making the much desired nose-riding capabilities of the surfboard applicable to other positions besides those on the wave crest where the rising motion of the water is pronounced.

Another object of the invention is to provide a surfboard of the character described in which variations in the degree of lift at the nose and midsections and stability can be achieved by varying the depth and the character of the concave or slotted areas.

These and other objects of the invention will become more apparent as the following description proceeds in conjunction with the accompanying drawings wherein:

FIG. 1 is a bottom plan View of the present surfboard with the concavity applied to the undersurface of the nose portion and midsection;

FIG. 2 is a view similar to FIG. 1 with the concavity applied to the midsection only;

FIG. 3 is a view similar to FIG. 1 with the concavity applied to the nose portion only;

FIG. 4 is a side elevational view of the board shown in FIG. 1;

FIG. 5 is a vertical sectional view taken on the line 55 of FIG. 1;

FIGS. 6-11 are sectional views similar to FIG. 5 illustrating modifications of the water trapping areas in the underside of the nose and midsection portions;

FIG. 12 is a fragmentary bottom plan view of the invention as applied to a modified surfboard;

FIG. 13 is a diagrammatic view, partly in vertical section, illustrating the manner in which the sidewisedisplaced water is trapped and converted to life; and

FIG. 14 is a diagrammatic view with the surfboard shown in side elevation illustrating the lift forces shown in FIG. 13.

Specific reference is now made to the drawings in which similar reference characters are used for corresponding elements throughout.

The surfboard is generally indicated at '10 and is an elongated buoyant member capable of being fabricated of a wide variety of materials, preferably fiberglasscovered, air-expanded plastic foam or balsam wood. The rider engages the upper or deck face 12 while the opposite bottom or undersurface 14 is adapted to engage the water. The bow 16 and stern or tail 18 are tapered and preferably upwardly curved to effect a. smooth sliding movement over the forefront of a wave. A skeg 20 depends from the after end of the board. Generally, the first third of the board from the forward tip 22 aft is considered the nose portion 24 which serves to lift the board over irregularities, the next third from the nose portion aft is considered the middle portion or midsection 26 which serves to sustain the weight, and the final third aft from the midsection to the rear end of the board is considered the rear stance planing position 27 which serves for steering.

Conventionally, the undersurface of these nose and middle portions of the board are convexly curved both longitudinally and transversely to prevent the tip 22 from catching irregularities on the waters surface and to ease the boards impact on wind chop and prevent slapping. However, when the rider walks to the middle or nose portion of the board and the wave is too small or too slow or his trimmed position on the wave is insufiicient to generate lift of magnitude required to support his weight, the nose portion dives under water and spills the rider. The present invention overcomes these disadvantages and extends the nose and/ or midsection riding capabilities to surfboard positions beyond those on the wave crest by providing liftgenerating means in the nose portion and/or midsection of the board as well as imparting greater speed. and maneuverability to the board.

This means in its broadest sense comprises a reversal of the curvature of the undersurface 14 of the nose portion 24 and/or midsection 26 of the board from convex to concave. This concavity can be confined to the midsection 26 as seen in FIG. 2, or to the nose portion 24 as seen in FIG. 3, or can occupy both areas as seen in FIGS. 1, 4, 13 and 14.

In the latter showing, this means is in the form of a slot in the under-surface of the nose portion 24 and midsection 26 which consists of a concave surface 28 that terminates short of the side edges 30 of the board to form sharp or rounded longitudinally extending corner portions 32 and relatively flat or rounded inwardly conerging longitudinal portions 34 therebeneath. From FIGS. 13 and 14 it will be seen that when the rider stands on the deck of the nose portion 24 or midsection 26 the wave therebenea-th, indicated by force lines 36, strikes the concave surface 28, a portion of which also turns into the corners 3'2, strikes the longitudinal portions 34 and reserves to produce a downward force F and therefore a reactive upward or lifting force R. Only a minor portion of the water is displaced sidewise. Thus, most of the water is entrapped beneath the nose portion and midsection of the board to create the lifting force.

The modification shown in FIG. 6 comprises a concavity 38 in the undersur-face of the nose portion 24 and/or midsection 26 which extends from one side edge 40 to the other edge 42 of the board, the side edges being here shown as sharp instead of feathered or rounded as in FIG. 5.

The modification shown in FIG. 7 comprises a plurality of longitudinally extending ridges 44 in the undersurface of the nose portion 24 and/or midsection 26 which are spaced transversely from one side edge 46 of the board to the other side edge 48, thereby producing longitudinally extending, transversely spaced indentations 50 to en'trap the side'wise-displaced water and convert it into lift. As shown in this figure, the ridges are preferably smooth and rounded although they can be sharp and their transverse spacing v-aried, if desired.

The modification of FIG. 8 is one in which the concavity 52 in the undersurface of the nose portion 24 and/or midsection 26 does not extend from one side edge 54 to the other side edge 56 of the board, but rather is centrally located symmetrically about the longitudinal axis of the board, is smoothly contoured and occupies only a predetermined area of the board.

The modification of FIG. 9 is similar to that of FIG. 8 except that the concavity 58 is sharper and narrower than concavity 52 and the remaining portions 68' and 62 of the undersurface' which extend to the side edges 64 and 66 of the board are convex, thereby combining the desiraible convex curvature of conventional boards with a means to increase lift in midsection and nose-riding stance areas.

The modification of FIG. is similar to FIG. 5. However, the central section 68 of the undersurface of the midsection 26 and/or nose portion 24 is convex but short of the side edges '70 and 72 of the board, longitudinal indentations 74 and 76 are provided which form inwardly converging substantially flat portions 78 and 80. Here again-the desirable convex curvature of the conventional board is combined with a means to increase lift in midsection and nose-riding stance areas.

The modification of FIG. 11 shows an area 82 in the undersurface of the nose portion 24 and/ or midsection 26 which terminates short of the rounded side edges 84 and 86 to thereby form longitudinal corner portions 88 and rounded diverging longitudinal portions 90 therebeneath. The'portion 82 may be cone-ave as shown in FIG. 5, or convex as shown in FIG. 10. The rounded corner portions 88 and diverging portions 90 are easier to fabricate and give a softer response.

It should be noted that the vertical depth of the depression or concavity can vary from shallow to a depth approximating the thickness of the board, can extend from the longitudinal axis of the board to as far as the outermost edges or less, and can occupy a portion or all of the nose portion area 24 and/ or midsection 26. The configurations of FIGS; 5, 7, 9 and 10 provide directional flow of water and directional stability as well as increased lift in the nose and midsection riding positions as compared to the smoothly arced configurations of FIGS. 6 and 8. The depression in the undersurface is symmetrical with respect to the longitudinal axis, concave in a transverse direction and either convexly curved along the loni gitudinal axis of the board or it may follow a straight line. In the latter case, the speed capability of the board will increase. As compared to a fiat or convex nose, a concavity having a depth of at least one-sixteenth of an inch of transverse arc and extending approximately half the width of the nose portion will yield a significant lift.

In FIG. 12, a portion of a surfboard 92 is shown of the construction shown and described in my Patent No. 3,160,897. The bottom face contains a rear tail surface 94 and a forward planing surface 96 which has a depending skeg 98, the surfaces being difierentiated by a transverse shoulder 100 so that the rider, by body movement or shift in weight, can bring the planing surface into partial or full play or bring the drag into effect thereby achieving a wide range of speeds while maintaining maneuverability throughout. The planing surface 96 which may extend to the front end or tip is provided with a depression or concavity as previously described hereinbefore with reference to all of the figures, although FIG. 12 shows the construction of FIG. 5 for illustrative and nou-limitative purposes, with like parts employing primed numbers. In this construction the overall maneuverability and stability of the surfboard both for the midsection and nose-riding stances is enhanced.

With reference to the concavity in the midsection, it should be noted that this section contacts the water nearly at all times regardless of where the rider is standing, front, middle or aft. Therefore, the depression or cavity in this midsection acts to raise the board somewhat by converting sidewise displaced water into lift force. This diminishes the cross-sectional area of the board immersed in the water thus lessening drag which in turn provides the board with greater speed and, by virtue of grooving less deeply in the water, provides greater maneuverability. This concavity in the midsection also has the effect of flattening the fore-and-aft curvature of a portion of the bottom thus creating a faster planing surface.

While preferred embodiments of the invention have here been shown .and described, skilled artisans" may make minor variations without departing from the spirit of the invention and the scope of the appended claims;

I claim:

1. A surfboard comprising an elongated buoyant member which is substantially solid in cross-section having a deck face, an opposite underface and front and rear ends, about the first third of said boards length from said front end aft constituting its nose portion, about the second third of said boards length aft of said nose portion constituting its mid-section, and about the remaining third of said boards length aft of said midsection to said rear end constituting its real stance planing surface, and means in the underface of said board forward of said rear stance planing surface providing at least one open concave area to entrap water and thereby increase lift at said concave area when the rider is positioned on said deck surface forward of said rear stance planing surface, said front and rear ends of said member being tapered and longitudinally upturned and said planing surface including a dependent skeg.

2. The combination of claim 1 wherein said concave area is located solely in said nose portion.

3. The combination of claim 1 wherein said concave aera is located solely in said midsection.

4. The combination of claim 1 wherein said concave area is located in both said nose portion and said midsection. I

5. The combination of claim 1 wherein said concave area extends from one side to the other and substantially the full length of said nose portion.

6. The combination of claim 1 wherein said concave area extends from one side to the other and substantially the full length of said midsection.

7. The combination of claim 1 wherein said concave area extends from one side to the other and substantially the full length of said nose portion and said midsection.

8. The combination of claim 1 wherein said means includes a plurality of longitudinally extending ridges forming transversely spaced, substantially concave open indentations between said ridges to impart directional flow to the water.

9. The combination of claim 1 wherein said open concave area extends substantially the full length of said nose portion symmetrically around the longitudinal axis of said board, the width of said concave area being less than the width of said board.

10. The combination of claim 1 wherein said open concave area extends substantially the full length of said midsection symmetrically around the longitudinal axis of said board, the width of said concave area being less than the width of said board.

11. The combination of claim 1 wherein said open concave area extends substantially the full length of said nose portion and said midsection symmetrically around the longitudinal axis of said board, the width of said concave area being less than the width of said board.

12. The combination of claim 1 wherein said means includes a pair of longitudinal open indentations adjacent the side edges of said board having downwardly and smoothly diverging portions.

13. A surfboard comprising an elongated buoyant member having a deck face, an opposite underface and front and rear ends, about the first third of said boards length from said front end aft constituting its nose porportion, about the second third of said boards length aft of said nose portion constituting its midsection, and about the remaining third of said boards length aft of said midsection to said rear end constituting its rear stance planing surface, and means in the underface of said board forward of said rear stance planing surface providing at least one open concave area to entrap water and thereby increase left at said concave area, said concave area terminating adjacent the side ends of said board, and longitudinal inwardly converging portions extending downwardly from the ends of said concave area to impart directional flow to the water.

14. A surfboard comprising an elongated buoyant member having a deck face, an opposite underface and front and rear ends about the first third of said boards length from said front end aft constituting its nose portion, about the second third of said boards length aft of said nose portion constituting its midsection, and about the remaining third of said boards length aft of said midsection to said rear end constituting its rear stance planing surface, and means in the underface of said board forward of said rear stance planing surface providing at least one open concave area to entrap water and thereby increase lift at said concave area, said means including a pair of longitudinal open indentations adjacent the side edges of said board having downwardly and inwardly converging portions, said surface of said nose portion between said indentations being convexly curved both longitudinally and transversely.

15. A surfboard comprising an elongated buoyant memher having a deck face, an opposite underface and front and rear ends, about the first third of said boards length from said front end aft constituting its nose portion, about the second third of said boards length aft of said nose portion constituting its mid-section, and about the remaining third of said boards length aft of said midsection to said rear end constituting its rear stance planing surface, and means in the underface of said board forward of said rear stance planing surface providing at least one open concave area to entrap water and thereby increase lift at said concave area, said front and rear ends of said board being tapered and longitudinally upturned, said planing surface including a depending skeg, and a transverse shoulder in said underface adjacent said skeg providing a tail surface above and aft of said planing surface.

16. The combination of claim 15 wherein said concave area terminates adjacent the side ends of said board and longitudinally inwardly converging portions extending downwardly from the ends of said concave area to impart directional flow to the water.

References Cited by the Examiner UNiTED STATES PATENTS 1,552,990 9/1925 Hunt 931O X 2,389,729 11/1945 Howland 9-3 10 3,027,575 4/1962 Fortin 9-310 3,160,897 12/1964 Kelly 93 l0 MILTON BUCHLER, Primary Examiner.

ALFRED E. CORRIGAN, Examiner. 

1. A SURFBOARD COMPRISING AN ELONGATED BUOYANT MEMBER WHICH IS SUBSTANTIALLY SOLID IN CROSS-SECTION HAVING A DECK FACE, AN OPPOSITE UNDERFACE AND FRONT AND REAR ENDS, ABOUT THE FIRST THIRD OF SAID BOARD''S LENGTH FROM SAID FRONT END AFT CONSTITUTING ITS NOSE PORTION, ABOUT THE SECOND THIRD OF SAID BOARD''S LENGTH AFT OF SAID NOSE PORTION CONSTITUTING ITS MID-SECTION, AND ABOUT THE REMAINING THIRD OF SAID BOARD''S LENGTH AFT OF SAID MID SECTION TO SAID REAR END CONSTITUTING ITS REAL STANCE PLANING SURFACE, AND MEANS IN THE UNDERFACE OF SAID BOARD FORWARD OF SAID REAR STANCE PLANING SURFACE PROVIDING AT LEAST ONE OPEN CONCAVE AREA TO ENTRAP WATER AND THEREBY INCREASE LIFT AT SAID CONCAVE AREA WHEN THE RIDER IS POSITIONED ON SAID DECK SURFACE FORWARD OF SAID REAR STANCE PLANING SURFACE, SAID FRONT AND REAR ENDS OF SAID MEMBER BEING TAPERED AND LONGITUDINALLY UPTURNED AND SAID PLANING SURFACE INCLUDING A DEPENDENT SKEG. 